What was found
AFTER TAKEOFF, NR 2 ENGINE OIL PRESSURE DECREASED TO 50 PSI VARING TO 60 PSI. PROP WAS FEATHERED AND RETURN TO FIELD. ALL OTHER ENGINE INDICATORS REMAINED NORMAL. LANDING UNEVENTFUL. FOUND EVIDENCE OF OIL LEAK IN DRAIN LINE FROM VARIABLE DELIVERS HYD PUMP. R & R HYD PUMP DRIVE OIL SEAL IAW AMM TASK 79-22-77-000-801 AND 79-22-77-400-801. PERFORMED ENGINE RUNS/LEAK CHECK IAW AMM TASK 71-00-00-790-801. NO LEAKS NOTED. OIL PRESSURE REMAINED IN NORMAL RANGES AND HELD STEADY. NO FURTHER DEFECTS. RETURNED TO SERVICE.